Heat radiating assembly and apparatus for permitting ice blocked water to drain off of house roofs

ABSTRACT

A heat radiating assembly and an apparatus using a plurality of heat radiating assemblies for melting ice on the roof thereby permitting ice blocked water to drain off of the roof. The heat radiating assembly comprises a flexible heat generating element, a shielding element for protecting the flexible heat generating element and for radiating heat produced by the flexible heat generating element, and an electric current source for heating up the flexible heat generating element. The roof ice melting apparatus utilizes a plurality of heat radiating assemblies with each one being spaced from the others and each one extends inwardly and upwardly from at least one roof edge. When heated up, the heat radiating assemblies of the roof ice melting apparatus create water draining channels to permit ice blocked water to drain off the roof due to melting of the ice located adjacent each heat radiating assembly.

United States atent [19'] Solin et a1.

[54] HEAT RADKATING ASSEMBLY AND APPARATUS FOR PERMITTING ICE BLOCKEDWATER TO DRAIN OFF OF HOUSE ROOFS [75] Inventors: Edward P. Solin,llion; Russell Post,

Fairfield, both of NY.

[73] Assignee: Arctic Roof Deicing Corporation,

llion, NY.

[22] Filed: June 1, 1971 [21] Appl. No.: 148,602

[51] Int. Cl. ..H05b 1/00 [58] Field of Search ..219/213, 345, 538, 544,546,

[56] References Cited UNITED STATES PATENTS 2,800,560 7/1957 Schrotteret al ..338/2l4 3,153,140 10/1964 Theodore et al. ...2l9/549 2,710,9096/1955 Logan et al ..338/214 X 2,111,251 3/1938 Spilsbury ..2l9/2l3 X3,214,571 10/1965 lndoe ..2l9/544 3,324,280 6/1967 Cheney et al.......2l9/544 2,507,039 5/1950 Miller ..2l9/2l3 [111 3,725,638 [4 1 Apr.3, 1973 3,141,955 7/1964 Culpepper 219/213 2,699,484 l/l955Michaels..... ....219/213 3,364,335 l/1968 Palatini et al ..2l9/2l3Primary Examiner-C. L. Albritton AttorneyHarry M. Weiss [57] ABSTRACT Aheat radiating assembly and an apparatus using a plurality of heatradiating assemblies for melting ice on the roof thereby permitting iceblocked water to drain off of the roof. The heat radiating assemblycomprises a flexible heat generating element, a shielding element forprotecting the flexible heat generating element and for radiating heatproduced by the flexible heat generating element, and an electriccurrent source for heating up the flexible heat generating element. Theroof ice melting apparatus utilizes a plurality of heat radiatingassemblies with each one being spaced from the others and each oneextends inwardly and upwardly from at least one roof edge. When heatedup, the heat radiating assemblies of the roof ice melting apparatuscreate water draining channels to permit ice blocked water to drain offthe roof due to melting of the ice located adjacent each heat radiatingassembly.

' 22 Claims, 12 Drawing Figures TEMPERATURE CONTROLLED SWITCHPATET-HEUAPM I975 ,725, 3

SHEET 2 [IF 2 FIG. 6 H6. 7

HEAT RADIATING ASSEMBLY AND APPARATUS FOR PERMIT'IING ICE BLOCKED WATERTO DRAIN OFF OF HOUSE ROOFS FIELD OF THE INVENTION semblies and roof icemelting apparatus for draining ice 1 blocked water off of house roofs.

BACKGROUND OF THE INVENTION A constant problem plaguing people living inhouses located in areas which have cold winters (where outsidetemperatures drop below the freezing point of 32 F) is that ice build upon the edge portions of their roofs prevents melted water from flowingor draining off the roofs.

Most houses are conventionally built with the edges of the roof (on bothsides of the house) overhanging the main frame of the house. Thisgeneral type of house construction employing a roof extending beyond theframe of the house has the practical value of providing some rainshielding for the main house frame. However, during the cold winterperiod the extended portion of the roof that overlaps the main houseframe becomes a serious liability and detriment to the home owner livingin a cold winter climate.

The large portion of the roof located above the main frame of the houseis generally heated somewhat due to the natural physical effect of theheat permeating up from the warmer house interior. This roof heatingeffect from the heat generated within the house alone or together withadditional roof heating caused by the sun (including sun heat reflectedby the roof exterior surface) melts snow and/or ice that is located onthis large roof portion. However, the extended or overlap roof portion,which is not directly over the main house frame, is not heated very wellby heat rising from the interior of the house and hence, tends to freezeinto ice any melted snow or ice water coming down the roof and reachingthis extended or overlap roof portion. Thus, a build up of ice occurs onthis extended or overlap roof portion to a level high enough to create acavity effect with one wall being formed by the ice build up on theextended roof portion. As a result of this ice wall being formed, meltedice or snow water coming down from the rest of the roof is not permittedto roll off the roof, but is blocked by the cavity wall. The water inthe cavity starts to build up and moves back up the roof to the level ofthe height of the ice wall formed on the extended roof portion. Thisback up water goes under the roof shingles and creates water leakageproblems for the home owner due to the ability of this back up water tofind openings in the roof.

While a great deal of thought has been given to this problem, nopractical solutions have been developed to relieve the home owner livingin a cold winter climate from the annoyance and damages caused by leakscoming through the roof of his house. In some instances, ceilings havebeen known to collapse under the build up of water created by leakingroofs. One proposed solution to this roof leakage problem was to run anelectric conductor or cable on the roof which was heated up by electriccurrent to melt roof ice, however, this solution was not effectivebecause of the danger of fire if the cable or conductor got too hot andbecause snow and ice movement on the roof caused the cables orconductors to be pulled completely or partially off the roof.

A need existed for the development of a technique, assembly or apparatusthat would solve the ice build up problem, but would be able to sustainsnow and ice movement on the roof and not be a fire hazard to the 0 homeowner. Furthermore, the assembly or apparatus that was needed to solvethis problem had to be able to withstand the substantial variations intemperature that were required of electric heating units that wereemployed for this roof ice buildup problem. Additionally, any electricheating units desirably had to have the additional features of beingquickly assembled, radiate sufficient heat, relatively inexpensive,rugged construction, dependable operation, and permit secure attachmentto house roofs.

SUMMARY OF THE INVENTION Accordingly, it is an object of this inventionto provide an improved heat radiating assembly.

It is another object of this invention to provide an improved apparatusfor permitting ice blocked water to drain off of house roofs.

In accordance with one embodiment of this invention, a heat radiatingassembly is provided which comprises a flexible heat generating element.The flexible heat generating element has an outer, flexible, moistureresistant, temperature variation insensitive, protective sheath and atleast one resistance wire located within the sheath. Shielding and heatradiating means are provided for protecting the flexible heat generatingelement and for radiating heat produced by the flexible heat generatingelement. Preferably, the shielding and heat radiating means is a metalsheath. Electric current source means are electrically connected to theresistance wire for heating the wire and for establishing this wire as aheat source for the shielding and heat radiating means. Additionally,temperature controlled switch means is electrically connected betweenthe electric current source means and the resistance wire of theflexible heat generating element for controlling the passing of currentto the resistance wire depending upon the temperature external to thetemperature controlled switch means. Preferably, the outer, flexibleprotective sheath of the flexible heat generating element is made ofsilicone rubber.

In accordance with another embodiment of this invention, an electricheat generating apparatus is provided for melting ice and permitting iceblocked water to drain off of a house roof. The apparatus comprises aplurality of heat radiating assemblies attached to the house roof. Eachof the plurality of heat radiating assemblies is spaced from each otherand extend inwardly and upwardly from at least one edge of the roof.Electric current source means are electrically connected to each of theplurality of heat radiating assemblies for permitting each of theplurality of heat radiating assemblies the capability of melting icelocated adjacent to each of the plurality of heat radiating assembliesthereby enabling ice blocked water located on the roof to drain off theroof through melted channels created by each of the plurality of heatradiating assemblies.

The foregoing and other objects, features and advantages of theinvention will be apparent from the following, more particulardescription of the preferred embodiments of the invention, asillustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of ahouse showing a plurality of heat radiating assemblies mounted on theroof and used as an apparatus for melting ice thereon.

FIG. 2 is a top view of the roof of the house of FIG. 1 showing a numberof heat radiating assemblies on both sides of the roof.

FIG. 3 is a top view similar to FIG. 2 showing a metal strip on two endsof the roof which is in contact with a number of heat radiatingassemblies located on both sides of the roof.

FIG. 4 is a view taken along the lines 4-4 of FIG. 1 showing themounting of a heat radiating assembly on the roof and its connection toa current source through a temperature controlled switch.

FIG. 5 is a sectional view of the heat radiating assembly as taken'alongthe lines 55 of FIG. 1.

, FIG. 5A is a sectional view similar to FIG. 5, but of anotherstructural configuration of a heat radiating assembly.

FIG. 6 is an enlarged, more detailed view of one of the heat radiatingassemblies of FIG. 1 looking at it from the top.

FIG. 7 is an enlarged, more detailed view of one of the heat radiatingassemblies of FIG. 1 looking at it from the bottom.

FIG. 8 is a front elevational view of the flexible heat generatingelement of one of the heat radiating assemblies of FIG. 1.

FIG. 9 is an enlarged, more detailed perspective view of one of the heatradiating assemblies of FIG. 1 with a bend therein for attaching to oneedge of the house roof.

FIG. 10 is a perspective view showing the location of one of the heatradiating assemblies of FIG. 1 in a metal, water directing, channel on ahouse roof.

FIG. 11 is an enlarged view showing an arrangement similar to that ofFiG. 10, but showing the heat radiating assembly located on one side ofthe metal channel.

DESCRIPTION Referring to FIG. 1, reference numeral 10 generallydesignates a house (shown in phantom lines) having a roof ice meltingapparatus thereon shown by a number of heat radiating assemblies 12mounted near the bottom edge portion of the roof. As can be seen withreference to FIG. 1, each one of the plurality of heat radiatingassemblies 12 is spaced from the others and, preferably, arranged in aparallel configuration. The

spacing between the heat radiating assemblies 12 can be varied asdesired to provide the most efficient roof ice heating arrangementdepending upon the particular winter climate the house is in, thematerial of the roof, the amount of heat radiated by each heat radiatingassembly 12, the size (or dimensions) of each heat radiating assembly12, etc. Preferably, each heat radiating as sembly 12 is from about 3feet to about 5 feet in length. As can be seen from FIG. 1, each heatradiating assembly 12 extends inwardly and upwardly from the edge of theroof of the house 10. v

Referring to FIG. 2, both edges of the roof of the house 10 of FIG. 1are shown having the heat radiating assemblies mounted thereon in themanner shown in FIG. 1. FIG. 3 is similar to FIG. 2, but shows a metalstrip M such as of aluminum (having a width of up to several feet)mounted and running along the edge portion of each side of the roof.Each metal strip M is, preferably, in physical contact with each of theheat radiating assemblies 12 located on the side of the roof associatedwith each metal strip M. In this manner, heat produced by each of theheat radiating assemblies 12 warms up each of'the metal strips M therebyfurther enhancing melting of snow and ice located near the roof edges.Thus, the build up of ice over the cold (overlap or extended) portion ofthe roof is prevented by the combined use of the metal strips M and theheat radiating assemblies associated therewith.

Referring to FIG. 4, one of the heat radiating assemblies of FIG. 1 isshown attached to the house roof. A roof shingle 14 (shown in phantom)is located on top of one end 15 of the heat radiating assembly. This isone illustrative form of attachment and other ways of mounting the heatradiating assembly on the roof can be used. Preferably, one shingle (14for example) is lifted and the end 15 of the heat radiating assembly isplaced under the shingle and nailed or screwed into the, for example,plywood located beneath the shingle. Then the shingle is lowered overand in contact with the end 15 and, if necessary, firmly attached to theroof.

The heat radiating assembly comprises a shield having preferably anouter section 16 and an inner section 18 (see FIG. 5 also). The heatradiating assembly also contains a flexible heat generating element 20(see FIG. 5 also) which is located between the outer section 16 and theinner section 18. In FIG. 4, the outer or upper section 16 is shownending substantially near the edge of the roof whereas the inner orbottom section 18 closely follows the contour around the roof edge asshown by reference numeral 17. This bottom or inner section 18 isfastened to the soffit by means of a screw or nail 19 thereby securelyholding the heat radiating assembly on the roof of the house at only twopoints (beneath the shingle 14 and under the softit). The flexible heatgenerating element 20 is shown looping around the roof edge to a pointwhere it is attached, for example, by adhesive or clamping means, to thebottom of the soffit. This loop of the heat generating element 20,because it is hot and the last thing the melted ice water touches goingoff the roof, is important because it serves to prevent any icicles frombeing formed at the roof edge where each heat radiating assembly islocated.

A terminal point 21 of the flexible heat generating element 20 is theportion where electric current is supplied to the flexible heatgenerating element 20. From I assemblies. If desired, an individualcurrent source can be applied to each heat radiating assembly byproviding individual outlets for each plug of the flexible heatgenerating element 20. In the embodiment of FIG. 4, a temperaturecontrolled switch 26 is shown electrically connected by means ofconductive lead or wire 28 to an alternating current source 30 which isconnected to or part of the house current. In this manner, thetemperature controlled switch 26 serves to electrically open or closethe circuit thereby respectively preventing or permitting current toflow to each of the heat radiating assemblies connected to the commonplug strip on molding 23. Thus, depending upon the temperature settingof the temperature controlled switch 26, the switch 26 closes or opensin relation to the external temperature at the switch 26. For example,it may be desirable to set the temperature controlled switch 26 to closeor pass current at an external temperature of about 35 F which isslightly above the 32 F freezing point in order to insure that the heatradiating assemblies would turn on'and warm up in time to prevent icebuild up on the roof. The heat radiating assemblies in their parallelconfiguration on the roof serve to, when heated up, create liquidchannels of melted ice thereby permitting any water build up on the roofto gravity flow or drain thereoff because of the drainage channelsprovided by the heated up heat radiating assemblies. Thus, while theheat radiating assemblies may not and probably will not melt all the icebetween each of the heat radiating assemblies because of spacingtherebetween, the water flow channels provided by the heated up heatradiating assemblies drain all pockets of water off of the roof therebypreventing any possibility of water back flow under the roof shingleswhich causes the undesirable house leakage problems describedpreviously.

The flexible heat generating element or the heat radiating assemblypreferably is about one to about twelve inches wide depending upon theheating that is desired. Preferably, a two or three inch width is moredesirable. In one example, using a five foot long heat radiatingassembly that has a flexible heat generating element about three incheswide provided, with the use ofa 110 Volt line and a current of 1.8 Amps,180 Watts of energy. Each heat radiating assembly can provide, ifdesired, a heating temperature of 100 F even though the outsidetemperature is at 0 F. The heating temperature provided by each heatradiating assembly can be varied depending upon the externaltemperature, material construction of the roof, etc.

The flexible heat generating element is preferably a RAMAFLEX (trademarkof the Rama Corporation of San Jacinto, Calif.) type of flexible heatingelement as described in their Hot Line Catalogue (I970 Copyright). Thisflexible heating element is constructed by utilizing a resistanceelement that is made by winding one or more fine nickel alloy wiresaround a glass string. A flexible outer sheath is made by laminating theresistance element between two sheets of glass cloth which have beenimpregnated with silicone rubber. The sheath is vulcanized underpressure to form a uniform, flexible, rubber sheath. Since theresistance element is imbedded in the rubber sheath, the chances ofhaving a fire because of shorting is substantially eliminated.Furthermore, the outer flexible sheath is moisture re-' sistant which isimportant to protect the resistant element since the heat radiatingassembly is constantly exposed to melted ice or snow during the winter.Additionally, the rubberized sheath of the flexible heating element 20is substantially temperature variation insensitive which is critical inavoiding destructive cracking under wide ranges of temperature to whichthe element 20 is subjected.

The upper section 16 and the lower section 18 are preferably made ofmetal such as aluminum which can be extruded to the shapes desired.Thus, the flexible heating element 20 is placed between metal sections16 and 18 which can be rapidly assembled together to provide the heatradiating assembly. Besides aluminum, copper, stainless steel orgalvanized metal can be used for the sections. The metal sections 16 and18 not only protect and shield the flexible heat generating element 20,but serve as a heat radiating means by radiating the heat generated bythe flexible heat generating element 20. While the sections 16 and 18are preferably of metal, it may be desirable in some circumstances orfor cost reasons to use non-metallic sections made of plastic, Teflon orNylon.

FIG. 5A is similar to FIG. 5 and illustrates another form of heatradiating assembly structure with the same reference numerals as used inFIG. 5 to designate the same parts with the addition of the letter A toeach numeral. In this embodiment, there are two metal sections 16A and18A except that the metal section 16A has two legs which rest againstthe roof providing an air space beneath the metal section 18A on whichis located the flexible heat generating element 20A. This type ofstructure is preferable also because it can be extruded relativelyinexpensively out of aluminum having a thickness of about 0.060 inch.The flexible heat generating element 20A or 20 (FIG. 5) has a thicknesswhich can vary from about 0.015 inch to about 0.055 inch. The metalsection 18 (FIG. 5) or 16A (FIG. 5A) have curved portions torespectively hold the end portions of the relatively flat metal section16 (FIG. 5) or 18A (FIG. 5A).

FIG. 6 is an enlarged view showing the top metal section 16 (See FIG. 5)held by the bottom metal section 18. FIG. 7 is an enlarged view from theopposite direction showing the bottom metal section 18 and the top metalsection 16.

FIG. 8 is an enlarged view of the flexible heat generating element 20(see FIG. 4). FIG. 9 is a perspective view of the heat radiatingassembly of FIG. 4 (without the flexible heat generating element 20).

FIG. 10 illustrates another embodiment where a heat radiating assembly200 is located in a metal water directing, channel M located on a houseroof. The heat radiating assembly is attached to the roof by two wires,for example, running from the end of the assembly 200 to'beneath twoshingles located on the roof. FIG. 11 is an enlarged view similar tothat of FIG. 10, but in this example the heat radiating assembly 200 islocated on one side of the metal channel M rather than in the centerthereof as shown in FIG. 10. In the FIG. 11 embodiment, one edge of theheat radiating element 200 is held by the edge or edges of one or moreroof shingles. The arrangement of either FIG. 10 or FIG. 11 permits theheat radiating assembly to heat up the metal channel M therebypermitting ice to melt thereon and the melted water to flow off theroof.

While the invention has been particularly shown and described withreference to the preferred embodiments thereof, it will be understood bythose skilled in the art that the foregoing and other changes in theform and details may be made therein without departing from the spiritand scope of the invention.

We claim: 1. An electric heat generating apparatus for melting ice andpermitting ice blocked water to drain off of a house roof comprising, incombination, a plurality of heat radiating assemblies attached to saidhouse roof, each of said plurality of heat radiating assemblies beingspaced from each other and extending inwardly and up wardly from atleast one edge of said roof; each of said heat radiating assembliescomprising a flat flexible heat generating element having an outer,flexible, moisture resistant, temperature variation insensitive,protective sheath, said heat generating element having at least oneresistance wire located within said sheath; flat, rigid, shielding andheat radiating means for protecting said flexible heat generatingelement and for radiating heat produced by said flat flexible heatgenerating element; and 7 electric current source means beingelectrically connected to said resistance wire of said flat flexibleheat generating element;

said electric current source means electrically connected to each ofsaid plurality of heat radiating assemblies for permitting each ofsaidplurality of heat radiating assemblies the capability of melting icelocated adjacent to each of said plurality of heat radiating assembliesthereby enabling ice blocked water located on said roof to drain offthrough melted channels created by each of said plurality of heatradiating assemblies.

2. The apparatus of claim 1 wherein each of said plurality of heatradiating assemblies having only one end portion attached onto saidroof.

3. The apparatus of claim 2 wherein said one end portion of each of saidplurality of heat radiating assemblies being attached to said roofunderneath a roof shingle.

4. The apparatus of claim 1 wherein eachof said plu rality of heatradiating assemblies being substantially parallel with respect to eachother.

5. The apparatus of claim 1 including a metal roof edge element runningalong said one edge of said roof and in contact with each of saidplurality of heat radiating assemblies.

6. The apparatus of claim 1 wherein each of said plurality of heatradiating assemblies being spaced from each other and extending inwardlyand upwardly from both lower edges of said roof.

7. The apparatus of claim 1 wherein each of said plurality of heatradiating assemblies being from about 3 feet to about 5 feet in length.i

8. The apparatus of claim 1 wherein each of said plurality of heatradiating assemblies being from about 1 to about 12 inches in width.

9. The apparatus of claim 7 wherein each of said plurality of heatradiating assemblies being from about 1 to about 12 inches in width.

10. The apparatus of claim 1 wherein said plurality of heat radiatingassemblies being electrically connected to ether.

1. The apparatus of claim 10 including temperature controlled switchmeans electrically connected between said electric current source meansand said plurality of heat radiating assemblies for turning saidassemblies on or off depending on the external temperature.

12. The apparatus of claim 1 wherein said outer, flexible sheath of saidflexible heat generating element comprising a rubberized layer.

13. The apparatus of claim 12 wherein said rubberized layer is asilicone rubber layer.

14. The apparatus of claim 1 wherein said shielding and heat radiatingmeans comprises a metal sheath surrounding said flexible heat generatingelement.

15. The apparatus of claim 14 wherein said metal sheath comprises afirst metal section and a second metal section, said flexible heatgenerating element being located between said first metal section andsaid second metal section.

16. The apparatus of claim 15 wherein said first metal section beingsubstantially flat, said second metal section having a first curvedportion and a second curved portion, one side end portion of said firstmetal section being held by said first curved portion of said secondmetal section, the other side end portion of said first metal sectionbeing held by said second curved portion of said second metal section.

17. The apparatus of claim 1 wherein said shielding and heat radiatingmeans comprises a non-metallic sheath surrounding said flexible heatgenerating element.

18. The apparatus of claim 17 wherein said nonmetallic sheath is made ofplastic.

19. The apparatus of claim 17 wherein said non- .metallic sheath is madeof Teflon.

20. The apparatus of claim 1 wherein said outer, flexible sheath of saidflexible heat generating element comprising a rubberized layer, saidshielding and heat radiating means comprises a metal sheath surroundingsaid rubberized layer.

21. The apparatus of claim 1 including a metal channel strip extendinginwardly and upwardly from said edge of said roof, one of said pluralityof heat radiating assemblies being in contact with said metal channelstrip.

22. The apparatus of claim 1 wherein said outer, flexible sheath of saidflexible heat generating element comprising a silicone rubber layer,said shielding and heat radiating means comprises a metal sheathsurrounding said silicone rubber layer, one end of said metal sheathbeing attached onto said roof, each of said plurality of heat radiatingassemblies being from about 3 feet to about 5 feet in length and fromabout 1 to about 12 inches in width.

1. An electric heat generating apparatus for melting ice and permittingice blocked water to drain off of a house roof comprising, incombination, a plurality of heat radiating assemblies attached to saidhouse roof, each of said plurality of heat radiating assemblies beingspaced from each other and extending inwardly and upwardly from at leastone edge of said roof; each of said heat radiating assemblies comprisinga flat flexible heat generating element having an outer, flexible,moisture resistant, temperature variation insensitive, protectivesheath, said heat generating element having at least one resistance wirelocated within said sheath; flat, rigid, shielding and heat radiatingmeans for protecting said flexible heat generating element and forradiating heat produced by said flat flexible heat generating element;and electric current source means being electrically connected to saidresistance wire of said flat flexible heat generating element; saidelectric current source means electrically connected to each of saidplurality of heat radiating assemblies for permitting each of saidplurality of heat radiating assemblies the capability of melting icelocated adjacent to each of said plurality of heat radiating assembliesthereby enabling ice blocked water located on said roof to drain offthrough melted channels created by each of said plurality of heatradiating assemblies.
 2. The apparatus of claim 1 wherein each of saidplurality of heat radiating assemblies having only one end portionattached onto said roof.
 3. The apparatus of claim 2 wherein said oneend portion of each of said plurality of heat radiating assemblies beingattached to said roof underneath a roof shingle.
 4. The apparatus ofclaim 1 wherein each of said plurality of heat radiating assembliesbeing substantially parallel with respect to each other.
 5. Theapparatus of claim 1 including a metal roof edge element running alongsaid one edge of said roof and in contact with each of said plurality ofheat radiating assemblies.
 6. The apparatus of claim 1 wherein each ofsaid plurality of heat radiating assemblies being spaced from each otherand extending inwardly and upwardly from both lower edges of said roof.7. The apparatus of claim 1 wherein each of said plurality of heatradiating assemblies being from about 3 feet to about 5 feet in length.8. The apparatus of claim 1 wherein each of said plurality of heatradiating assemblies being from about 1 to about 12 inches in width. 9.The apparatus of claim 7 wherein each of said plurality of heatradiating assemblies being from about 1 to about 12 inches in width. 10.The apparatus of claim 1 wherein said plurality of heat radiatingassemblies being electrically connected together.
 11. The apparatus ofclaim 10 including temperature controlled switch means electricallyconnected between said electric current source means and said pluralityof heat radiating assemblies for turning said assemblies on or offdepending on the external temperature.
 12. The apparatus of claim 1wherein said outer, flexible sheath of said flexible heat generatingelement comprising a rubberized layer.
 13. The apparatus of claim 12wherein said rubberized layer is a silicone rubber layer.
 14. Theapparatus of claim 1 wherein said shielding and heat radiating meanscomprises a metal sheath surrounding said flexible heat generatingelement.
 15. The apparatus of claim 14 wherein said metal sheathcomprises a first metal section and a second metal section, saidflexible heat generating element being located between said first metalsection and said second metal section.
 16. The apparatus of claim 15wherein said first metal section being substantially flat, said secondmetal section having a first curved portion and a second curved portion,one side end portion of said first metal section being held by saidfirst curved portion of said second metal section, the other side endportion of said first metal section being held by said second curvedportion of said second metal section.
 17. The apparatus of claim 1wherein said shielding and heat radiating means comprises a non-metallicsheath surrounding said flexible heat generating element.
 18. Theapparatus of claim 17 wherein said non-metallic sheath is made ofplastic.
 19. The apparatus of claim 17 wherein said non-metallic sheathis made of Teflon.
 20. The apparatus of claim 1 wherein said outer,flexible sheath of said flexible heat generating element comprising arubberized layer, said shielding and heat radiating means comprises ametal sheath surrounding said rubberized layer.
 21. The apparatus ofclaim 1 including a metal channel strip extending inwardly and upwardlyfrom said edge of said roof, one of said plurality of heat radiatingassemblies being in contact with said metal channel strip.
 22. Theapparatus of claim 1 wherein said outer, flexible sheath of saidflexible heat generating element comprising a silicone rubber layer,said shielding and heat radiating means comprises a metal sheathsurrounding said silicone rubber layer, one end of said metal sheathbeing attached onto said roof, each of said plurality of heat radiatingassemblies being from about 3 feet to about 5 feet in length and fromabout 1 to about 12 inches in width.